Fuel injection system



March 11, 1969 F. B. SWEENEY FUEL INJECTION SYSTEM Sheet of 5 Filed March 25, 1966 95 FIG. 2 I01 INVENTOR. FRANK B. SWEENEY llfim ATTORNEYS March 11, 1969 B, W N 3,432,152

FUEL INJECTION SYSTEM Filed March 25, 1966 Sheet 2 of s 26 22 IO I I II 96 l v 23 (IQ 9? 0 2| IOI'\- 5 95 I03 29 I02 9 I 39 1 30 |O5 {3 38 47 48 as 1 C) i FIG. 3

INVENTOR.

FRANK a. SWEENEY ATTORNEYS March 11, 1969 F.1B. SWEENEY 3,432,152

FUEL INJECTION SYSTEM 7 Filed March 25, 1966 FIG. 5

INVENTOR. FRANK B. SWEENEY BY I W MM ATTORNEYS United States Patent 3,432,152 FUEL INJECTION SYSTEM Frank B. Sweeney, 947 Meigs St., Rochester, NY. 14620 Filed Mar. 25, 1966, Ser. No. 537,332 US. Cl. 261-34 30 Claims Int. Cl. F02m 59/20, 45/12 ABSTRACT OF THE DISCLOSURE A fuel injection system: meters pressurized fuel into the engines intake manifold in response to the sensing of air movement above the throttle valve and includes a pressure regulator responsive to output pressure, throttle position, and manifold vacuum, and a vapor separator that is in equilibrium relative to fuel pressure for operating independently of fuel pressure to separate vapor and provide a continuous bleed back to the tank.

This invention relates to a fuel injection system for an internal combustion engine.

The basic principles of carburation have remained unchanged for many years, and many suggested innovations have been failures. Although there have been some suggestions for pressurized, fuel injection systems, standard automotive carbrurationstill uses a venturi to draw fuel into the stream of air rushing into the engine through the carburator. Fuel injection systems have been complex, costly, inefficient, and generally unsatisfactory for automotive needs.

The objects of this invention include, but are not limited to, the following:

(a) Overcoming the deficiencies and failures of prior art fuel injection systems;

(lb) Improving fuel injection to make it commercially and functionally feasible for mass produced automobiles;

(c) Supplying an engine with a mixture of air and wellatomized fuel that accurately meets the varying needs of the engine under different conditions;

(d) Reducing the vapors and fumes emitted into the atmosphere by operation of an internal combustion engine;

(e) Completely shutting off the fuel to an internal combustion engine when the engine is stopped, and eliminating leakage from the fuel system of a stopped engine to reduce waste and air-polluting vapors and to reduce fire hazards from accidents;

f) Supplying engine fuel in an efficient and economical manner and yet enabling the engine to realize its performance potential;

(g) Providing a fuel injection system that can be readily interchanged with standard carburators, and that is attractive in appearance, light in weight, compact, low in overall height, and formed 'of relatively few and simple parts;

(h) Providing a fuel injection system that can be readily adapted to fit the particular needs of many different engines;

(i) Using a single nozzle system and a single idle adjustment on a fuel injector suitable for operation with a split intake manifold;

(j) Making a fuel injection system automatically responsive to variations in atmospheric pressure and not adversely affected by location or environment;

(k) Enriching the fuel-air mixture for an internal com.- Ibustion engine operating under a heavy. load, momentarily supplying additional enriched fuel for rapid acceleration of the engine, and greatly reducing the fuel admitted to the engine during deceleration;

(l) Enriching the fuel-air mixture for starting a cold engine and adjusting the richness of the mixture as the engine warms up;

(m) Reducing the vaporizing of fuel and separating vapor from the fuel supplied to an engine; and

(11) Making a fuel injection system compatible with existing intake manifolds, throttle linkages, vacuumoperated accessories, bimetallic thermo-control devices actuated by manifold temperature, and. other c'anburatorassociated equipment.

These and other objects of the invention will be apparent hereinafter from the specification, which describes the invention, its use and operation, and its preferred embodiment, from the drawings, which constitute a part of the disclosure, and from the subject matter claimed.

Generally, my inventive system uses several components in a well-integrated and balanced relationship to supply optimum fuel-air mixtures to an internal com bustion engine. These components interact extensively to meet all the needs of modern carbura'tion. The components include a regulator for variably controlling fuel pressure according to the needs of the engine, a vapor separator for removing vapor from liquid fuel to be injected into the engine, and a meter responsive to the needs of the engine for controlling the injection of the variably pressured. fuel into the engines intake. In addition, a cold starting enrichment mechanism cooperates with other components to provide an enriched fuel air mixture variable to suit the engines needs as it is started cold and warmed up. Each of the components has many features cooperating to provide optimum fueling of the engine, maximum safety, and minimum air pollution.

In the drawings:

FIG. 1 is a top plan view of a preferred embodiment of fuel injector according to the invention;

FIG. 2 shows a partially cut-away elevation of the side of the injector as illustrated in FIG. 1;

FIG. 3 shows a partially cut-away elevation of the side of the inventive injector that is lowermost in FIG. 1;

FIG. 4 is a section of the injector of FIG. 1 taken along the line 44;

FIG. 5 is a section of the injector of FIG. 1 taken along the line 5-5; and

FIG. 6 is a partial section of an alternate pressure regulator.

Throughout the drawings, corresponding parts are identified by the same reference numerals.

Although the inventive injection system can be accomplished in a variety of embodiments, for convenience, the invention will be disclosed in relation to the preferred illustrated embodiments of an injector that is interchangeable with a standard carburator for an automobile. The structure of the various components of the preferred injector will first be described, and then the operation of the injector under varying condiitons will be explained.

SYSTEM, GENERALLY As best shown in FIG. 1, the inventive system includes a body 9 forming an inlet passage including an air horn 15 and secured to an intake manifold (not shown) of an internal combustion engine. Preferably grouped around and secured to the outside of body 9 are a pressure regulator 10, a vapor separator 11, a fuel metering device 12, and starting enrichment and throttle linkage members 13. Air valve 14 is pivotally mounted within air horn 15 for interaction with the metering mechanism 12. Generally, fuel from a tank (not shown) is pumped under pressure by a fuel pump (not shown) to pressure regulator 10 which controls fuel pressure according to the needs of the engine; vapor is preferably removed from the pressure-regulated fuel in vapor separator 111, and the variably pressured fuel is metered into the engine by metering device 12 which is responsive to air valve 14. The structure of these components will be described separately, and then the operation of the inventive system will be explained.

PRESSURE REGULATOR Referring first to FIG. 3, fuel pumped under pressure from a fuel pump (not shown) is admitted to pressure regulator through inlet passage 20. From passage 20,

'fuel enters a relatively high-pressure inlet chamber 21 including a bafile 22 arranged to reduce turbulence in fuel in chamber 21. The remaining structure of pressure regulator 10 is better shown in the section view of FIG. 5. An alternate pressure regulator 10' is shown in FIG. 6, and will be described after pressure regulator 10 is explained.

Communicating with chamber 21 is a pressure-regulating valve formed as a shaped pin 23 and fuel passageway 24 in which pin 23 is movubly disposed. Pin 23 can be formed in any shape required for the needs of the engine such as convex or concave curvatures. Normally, however, a linear taper is preferred.

Chamber 21 is bounded by side wall 19 and is closed by a screw-threaded cap 25 that is adjustable variably to compress spring 26 that biases pin 23 downward toward a closed position. By such adjustment, cap 25 regulates the minimum pressure of fuel for idling of the engine. Near the top of cap 25 an annular, encircling groove 27 is formed, and an O-ring 28 is disposed in groove 27. O-ring 28 presses against wall 19 of chamber 21 and sesals fuel within chamber 21 for any adjustment of cap 2 A pair of diaphragms 29 and 30 are arranged below valve pin 23, and the lower end of pin 23 is secured to abutment member 31 the lower end of Which engages upper diaphragm 29. The downward bias of spring 26 keeps abutment member 31 in engagement with diaphragm 29 so that pin 23 moves with regular diaphragm 29.

As an alternative the illustrated coupling of pin 23 with regulator diaphragm 29, a spring can be interposed between diaphragm 29 and pin 23. The coupling arrangement selected affects the taper or shape of pin 23 for optimum operation.

Regulator diaphragm 29 is responsive to the position of power diaphragm 30 through a resilient intercoupling preferably in the form of regulator spring 32 engaging the upper surface of diaphragm 30 and the underside of spring housing 33 to urge diaphragms 29 and 30 apart. Housing 33, which rests against the under surface of diaphragm 29, extends downwardly toward the upper surface of diaphragm 30, and is normally spaced a small amount therefrom. Power spring 34 engages power disk 35 and the bottom 36 of the housing for pressure regulator 10 for biasing disk 35 and diaphragm 30 upward. Bottom 36 of the housing for regulator 10 is preferably formed integrally with body 9, but it and the entire regulator can be readily located remotely from body 9.

Vacuum chamber 37 communicates with the intake manifold of the engine through conduit 38 connecting with the intake manifold below the throttle valve for the system. Conduit 38 preferably connects with the intake manifold through passage 111 (FIG. 4) leading to vacuum connector socket 110 (FIG. 4) for vacuum-powered accessories. Vacuum chamber 37 is sealed from the atmosphere not only by diaphragm 30, but by downwardly extending sleeve 49 of power disk 35 engaging the outside of bushing 50. Through conduit 38 and vacuum chamber 37, the underside of disk 35 and diaphragm 30 are subjected to the relatively low pressure of the intake manifold. Larger pressure on the upperside of diaphragm 30 tend to force diaphragm 30 downward against the bias of power spring 34 as a function of the vacuum in chamber 37.

A preferably heat-insulating member 39 mounted on the top of bottom member 36 and diaphragm 30 forms a portion of the housing of regulator 10 and defines a chamber 40 between power diaphragm 30 and regulator diaphragm 29. Chamber 40 is preferably maintained at atmospheric pressure through a vent 41 to the atmosphere outside the injector. Insulator member 39 also insulates fuel in the upper portion of regulator 10 from heat rising from the relatively hotter lower sections of body 9 connected to the intake manifold of the engine. Of course, such insulation can be eliminated When the regulator is positioned elsewhere away from engine heat. The upper portion of the housing for regulator 10 is preferably formed of body 51.

Delivery passage 42 provides an outlet for fuel at variably regulated pressures from regulator 10, and through passage 43, a chamber 44, communicating with the upper surface of regulator diaphragm 29, is filled with fuel at variable output pressures. Regulator diaphragm 29 is thus subjected to output fuel pressure on its upper surface.

The inventive regulator is preferably responsive to the engines throttle. Through linkages with an accelerator pedal (not shown), throttle shaft 45 is rotationally positioned in a well-known way for controlling throttle valve 46 (FIG. 4) to regulate the speed of the engine. For a split intake manifold for which the illustrated injector is intended, a pair of throttle valves 46 are mounted on throttle shaft 45 for throttling each intake.

As shown in FIG. 5, cam 47 also rotates with throttle shaft 45 for positioning follower 48 which slides vertically in bushing 50. As illustrated, throttle shaft 45 is in the off or idle position, but as throttle shaft 45 is turned toward open throttle positions, follower 48 is raised by cam 47.

In summary, the forces at work in pressure regulator 10 preferably include downward bias of spring 26 against pin 23 transmitted to regulator diaphragm 29 which is also urged downward by fuel under pressure in chamber 44. Upward forces preferably include the position of follower 48 and the bias of power spring 34 which is countered by vacuum in chamber 37. The forces operating between the two diaphragms 29 and 30 include atmospheric pressure in chamber 40 and the compressive force of regulator spring 32.

An alternative fuel pressure regulator 10' is shown in section in FIG. 6, which corresponds to the view of regulator 10 as shown in FIG. 5. Regulator 10 is a single diaphragm embodiment designed to be interchangeable with regulator 10 in the inventive injector.

The upper portion of regulator 10' has been omitted from FIG. 6, since it is preferably the same as illustrated for pressure regulator 10. Thus, pressure regulator valve pin 23, fuel passageway 24, inlet chamber 21, valve spring 26, and cap 25 are preferably the same for either pressure regulator and have been omitted from FIG. 6.

Among the illustrated portions of pressure regulator 10, body 9, throttle shaft 45, throttle cam 47, follower pin 48, bushing 50, regulator housing bottom 36, upper regulator housing 51, fuel delivery passage 42, passage 43, and chamber 44 are all the same as illustrated in FIG. 5 for pressure regulator 10. Pressure regulator diaphragm 125 is similar to diaphragm 29 as illustrated for regulator 10, but its function in regulator 10" is somewhat different.

Preferably, heat-insulating spacer (corresponding to a similar spacer 39 in FIG. 5) forms a chamber 116 below diaphragm 125, and chamber 116 is maintained at atmospheric pressure through vent 117. Regulator disk 118 underlies regulator diaphragm 125 and is engaged by the upper end of regulator spring 119.

A coupling member rides atop follower pin 48 in a sliding fit with the outside of bushing 50; the lower end of coupler 120 is provided with a flange 121 for supporting the lower end of regulator spring 119. By such an arrangement, the throttle position sets cam 47, and vertically positions both follower pin 48 and coupling member 120.

Regulator spring 119 is compressed between coupler 120 and regulator disk 118 to position regulator diaphragm 125 vertically as a function of both throttle position and fuel pressure in chamber 44. In turn, abutment member 31 and pressure regulator valve pin 23 (as in FIG. 5) are positioned for regulating the pressure in fuel in delivery passageway 42.

VAPOR SEPARATOR Vapor separator 11 preferably connects with delivery passage 42 for receiving fuel under variable pressure from regulator 10. As best shown in FIG. 5, vapor separator 11 is prefer-ably housed in body 51 which also forms the upper housing for pressure regulator 10. Thus, insulator member 39 also insulates vapor separator 11 from the heat from the intake manifold since vapor separator 11 is integral with the upper portion of pressure regulator 10. However, the inventive vapor separator can readily be positioned elsewhere, remote from engine heat, or in a separate housing.

A chamber 52 formed in vapor separator 11 is filled with fuel under the pressure set by regulator The top of chamber 52 is closed by a cap 53 that is screwthreaded into housing 51. Above the threads on cap 53 is formed an annular, encircling groove 54, and O-ring 55 is disposed in groove 54 for forming a seal between cap 53 and housing 51 to keep fuel from leaking out of chamber 52.

A baflle 56 is arranged in chamber 52 for minimizing turbulence in fuel within chamber 52. Float 57 is immersed in fuel chamber 52 for seeking a vertical position as a function of the proportion of fuel and vapor within chamber 52. Float 57 is in equilibrium relative to the pressure in chamber 52 since the entire external surfaces of float 57 are subjected to the pressure within chamber 52 at all times and for all pressures. Especially since the upper and lower surfaces of float 57 are under the same pressure, float 57 is not moved up or down for any pressure within chamber 52, and is positioned solely in response to floatation as a function of the fuel-vapor ratio.

Float 57 is preferably guided for vertical motion by projections 58 extending inward from baflle 56, and is preferably held from wide contact with the bottom of chamber 52 by a dimple 59 formed in the bottom of float 57. This insures that float 57 is at all times free for vertical floating motion within chamber 52 without sticking or binding.

Valve pin 60 is disposed atop float 57 to be positioned vertically by boat 56. Chamber 52 extends above valve pin 60 for equalizing pressure OnbOfit 57 as explained above. Valve pin 60 slides vertically within valve slot 61 formed in bushing 63. Preferably symmetrically arranged ports 62 open into valve slot 61 and communicate with an annular groove 64 around the outside of bushing 63. A vapor passageway 65 communcates with groove 64 and leads from vapor separator 11 to a lower pressure region. Preferably, vapor passage 65 leads from near the top of chamber 52, as illustrated, back to a fuel storage tank (not shown).

The vertical position of valve pin 60 in slot 61 determines the extent to which ports 62 are opened to let vapor or fuel pass to outlet passage '65. The upper portion of valve pin 60 is preferably tapered to prevent a rush of vapor or fuel from chamber 52 into outlet passageway 65 as valve pin 60 drops .to uncover the upper edges of ports 62. Stop screw 66 is adjustably turned down into chamber 52 for limiting the upward motion of valve pin 60 to allow a continuous minimum bleed of vapor or fuel from chamber 52 through outlet passage 65 to a fuel storage tank. Screw 66 is sealed by O-ring 67.

Vapor passage 68 is arranged for leading vapor from metering mechanism 12 back to vapor separator 11 for escape through vapor passage 65. Fuel outlet passage 69, preferably arranged near the bottom of vapor separator 11, conducts fuel under variably regulated pressure to metering mechanism 12 for injection into the engine in- 6 take. Passages 68 and 69 are also illustrated in FIG. 1.

METERING DEVICE The structure of metering device 12 is best shown in the section view of FIG. 4.

Housing 70 for metering device 12 is preferably disposed outside of air horn 15 and secured to a side wall of body 9; it is preferably spaced from the wall of body 9 by a heat-insulating member 71. Insulator 71 protects housing 70 and the fuel therein from the relatively hot body 9 mounted on the engine intake manifold.

Inlet chamber 72 formed within housing 70 is filled with fuel at the pressure variably regulated by the regulator 10. The end of chamber 72 is sealed by a cap 73 that is crew-threaded into the end of housing 70 and sealed by O-ring 74 arranged in groove 75 in cap 73. Oring 74 seals fuel within chamber 72 and allows cap 73 to be screwed in and out of position in housing 70 without impairing the seal.

The metering of fuel from chamber 72 into air horn 15 is controlled by shaped pin 76 which can have any desired shape dictated by the needs of the engine, and as illustrated, is preferably tapered. Pin 76 moves axially in a metering aperture 77 which affects the .rate of fuel injection. From aperture 77, metered fuel passes along pin 76, through passageway 78, and through nozzle 79 which extends preferably into air horn 15 to inject fuel through a pair of side apertures 109. Thus, the pressure on fuel in chamber 72, and the size of aperture 77, cooperate to control the rate of fuel delivery through nozzle 79 to the engine intake. Nozzle 79 can be positioned elsewhere in the engines intake, but if it is located in a low pressure region below air valve 14, a bleed from atmosphere through the nozzle should be arranged to compensate for the lower pressure applied to the nozzle in such location.

Housing 70, chamber 72, and metering pin 76 are preferably angled upward toward nozzle 79 as illustrated. Preferably, in the upper corner of chamber 72, vapor passageway 80 is formed to lead any vapor in chamber 72 through passage 80 and vapor conduit 68 back to vapor separator 11 as previously described.

Metering pin 76 is preferably supported at both ends so as to be centered in aperture 77 and to move axially therein without touching the walls of aperture 77. This prevents wear and improper function of metering pin 76. For this purpose, the rearward end of metering pin 76 is formed as a piston 81 mounted for movement in a cylinder 82 arranged in chamber 72. The forward end of metering pin 75 is seated in a recess in pin-supporting member 83 which is slidable in bore 84. Piston 81 is formed with a plurality of openings 85 to allow fuel to pass piston 81 enroute to aperture 77. Chamber 72 thus functions as a dashpot for piston 81.

Ahead of piston 81, and behind the shaped portion of pin 76, is formed an annular, encircling groove 86 in which O-ring 87 is disposed. O-ring 87 is arranged to seat against aperture bushing 88 to shut off fuel to aperture 77. Recessing of aperture 77 in bushing 88 is preferred to space the metering aperture from the shut off seat and to provide a straight-line flow path for fuel approaching the metering aperture. This facilitates accurate metering.

Movement of the metering pin 76 is controlled by spring 89 engaging cap 73 and piston 81 for biasing pin 76 toward a closed-valve position, and by the: counterforce of air valve 14 applied against pin-supporting member 83 as will be explained.

Air valve 14 is eccentrically mounted on pivot shaft 90 in air horn 15. Such mounting is also illustrated in FIG. 1. The longer lever arm of air valve 14 thus outweighs and overbalances its shorter lever arm so that air valve 14 tends to swing toward the vertical position illustrated in broken lines in FIG. 4.

Air valve 14 is not a valve in the sense that it opens and closes to govern the amount of air passing through air horn 15, but rather acts as a sensing means, the position of which is set by the force of air moving through air horn 15. Throttle valve 46 can be set anywhere between its solid-line and broken-line positions illustrated in FIG. 4 to govern the amount of air passing through air horn 15, and air valve 14 is moved to a position responsive to the force of such air movement.

As shown in FIGS. 1 and 4, a generally U-shaped equalizer bracket 91 is pivotally secured to the up-turning, shorter-lever-arm side of air valve 14 for transmitting motion of air valve 14 to pin-supporting member 83. The leg ends 92 of equalizer bracket 93 are loosely and pivotally secured within mounting bracket 93 and the opposite, curved end of equalizer bracket 91 is loosely lodged in a slot 94 in the end of pin-supporting member 83. The two legs of equalizer bracket 91 help balance the force of air valve 14 and transmit it evenly to pin-supporting member 83 without any sticking or binding. Thus, the position of metering pin 76 is determined by the position of air valve 14 opposing spring 89.

STARTING ENRICHMENT The inventive system preferably includes a starting enrichment device powered by a well-known bimetallic element (not shown) responsive to engine temperature. Force from such an element is transmitted through linkage shaft 95 to lever 96 secured to pivotal shaft 97. When the engine is cold, lever 96 is moved to the position best shown in FIG. 5 in which a limit surface 99 engages stop 98. As the engine warms, lever 96 is driven clockwise (as illustrated in FIG. 5) until limit surface 100 engages stop 98. Such motion of lever 96 is transmitted to shaft 97 for controlling the inventive starting enrichment device.

Shaft 97 extends across body 9 as shown in FIG. 3, and lever 101 is fastened to the opposite end of shaft 97, as best shown in FIG. 2. Through linkage arm .102, pivotal motion of lever 101 is transmitted to step cam 103 for driving cam 103 through angular positions. Idle adjustment screw 104 of throttle lever 105 bears against step cam 103 so that the position of step cam 103 determines the minimum idle speed setting of throttle lever 105.

A cantilever leaf spring 106 is secured to lever 101 by screw 107, and spring .106 tends to extend in a straight line from its anchored position under screw 107. As best shown in FIG. 2, spring 106 is bent around lever 101 and deflected from its normal position by a maximum amount, because shaft 97 is positioned in its extreme cold start position. The free end of spring 106 engages lever 108 which is secured to shaft 90 on which air valve 14 is also secured. Thus, in the position illustrated in FIG. 2, spring 106 tends to drive lever 108 counterclockwise to rotate shaft 90 counterclockwise for opening air valve 14. However, spring 106 is preferably arranged to be not sufiiciently strong to actually open air valve 14, but merely to bias air valve 14 toward an open position so that it opens wider than normal under the force of air moving through air horn 15.

As shaft 97 is rotated in response to gradual warm-up of the engine, a lever 101 is rotated counterclockwise as viewed in FIG. 2 to drive step cam 103 clockwise for gradually decreasing the minimum idle for throttle lever 105. Also, such motion diminishes the bias of spring 106 as applied to lever 108 and shaft 90 for lessening the opening bias on air valve 14.

OPERATION The operation of the inventive system will be described from the cold start position illustrated in the drawings, through cranking and starting the engine, fast idle and enriched warm-up, normal idle, acceleration, high speed and load conditions, deceleration, and stop. The description will first refer to the injector illustrated in FIGS. 1-5 including the two-diaphragm pressure regulator 10, and then the difference in operation with the single diaphragm pressure regulator will be explained.

For a cold start, all the elements of the inventive system are positioned as illustrated in the drawings. Lever 96 is set in its illustrated position by rod in response to the force of a thermosensitive bimetallic member (not shown). With shaft 97 in its illustrated position, lever 101 is positioned as shown in FIG. 2 to hold step cam 103 in its maximum idle position and to exert maximum opening bias on air valve 14 through spring 106, lever 108, and shaft 90. Air valve 14, throttle valve 46, and metering pin 76 are all closed, shutting off both fuel and air to the engine.

The engine is then cranked, which draws air through air born 15, and opens air valve 14 slightly. The opening of air valve 14 in response to cranking of the engine is increased because of the bias of spring 106 applied to shaft 90. Movement of air valve 14 is transmitted through coupler 91 to pin-supporting means 83 for moving metering pin 76 back to unseat O-ring 87 from aperture bushing 88 and open aperture 77 for admitting fuel to the engine through nozzle 79.

Throttle lever 45 and valve 46 are opened as the engine is cranked to admit air to the engine, and the throttle is held at a fast idle postion by step cam 103 to allow more than normal idling air to rush into the engine through air horn 15. This causes further opening of air valve 14 and further increases the opening of aperture 77 for injection of more fuel.

Cranking the engine also reduces the pressure n the intake manifold and creates a vacuum in chamber 37 to draw power diaphragm 30 and power disk 35 doWn onto follower pin 48 riding on throttle cam 47. Cranking also operates a fuel pump (not shown) to supply fuel under pressure to regulator 10.

Starting can be assisted by rapidly opening the throttle to advance throttle cam 47 and drive follower pin 48 suddenly upward. This raises diaphragm 30 rapidly and in turn drives regulator diaphragm 29 upward to evacuate fuel from chamber 44 into the pressure regulator outlet passageway 42. This increases the fuel pressure at the metering device 12 and injects extra fuel into air horn 15 for a richer starting mixture.

As the engine starts, it speeds up, drawing more air through air horn 15 and opening air valve 14 further still under the bias of spring 106. Such opening of air valve 14 forces metering pin 76 further rearwardly and enlarges the metering aperture 77 to increase the rate of fuel injection through nozzle 79. The engine continues idling rapidly under control of step cam 103 during warmup. The engine receives its full air supply through the un choked, open throttle, and receives an enriched fuel-air mixture through the increased opening of air valve 14 and metering pin 76.

Such a starting arrangement is different from, and ad vantageous over, the usual choke method which decreases the air supply to the engine for a cold start. Allowing the engine to have its normal air supply and enriching the fuel-air mixture is a more natural starting arrangement than a choke. Plenty of air is available for burning the fuel admitted to the engine, and this avoids unburned fuel running down the cylinders and into the crank case to dilute the engines lubricating oil. Also, warm-up is faster, and a partly warmed engine performs better under the inventive enriching system.

As the engine gradually warms, shaft 97 and lever 101 are moved to drive step cam 103 toward the normal idle position relative to throttle 105 and to decrease the air-valve-opening bias of spring 106 as applied to lever 108 and shaft 90. Through this, engine idle gradually slows to normal, and air valve 14 approaches a nearly closed, normal idle position.

At normal idle, power disk 35 rests on the top of follower pin 48 to allow power diaphragm 30 and regulator diaphragm 29 to assume their lowermost positions. In such relation, the fuel pressure regulated by pin 23 is adjusted for a normal minimum by the position of cap 25 controlling the downward bias of spring 26 on pin 23. A mechanical coupling between follower pin 48 and disk 35 is maintained at idle speed and throughout relatively low engine speeds and low load conditions. Low pressure idling fuel, combined with low air intake through air horn 15, injects only a sustaining trickle of fuel through nozzle 79 to the engine.

If the throttle is opened gently from idle position to accelerate the engine to higher speeds, follower pin 48 is driven upward to force disk 35 and power diaphragm 30 upward. Upward movement of power diaphragm 30 compresses a regulator spring 32 and drives regulator diaphragm 29 upward a lesser amount. Upward motion of regulator diaphragm 29 is transmitted to regulator valve pin 23 to open such valve further and increase the pressure of fuel delivered from regulator through delivery passageway 42 to metering means 12. Opening of throttle 46 for faster engine speeds also causes greater flow of air through air horn and opens air valve 14 a greater amount to increase the size of metering aperture 77 for injecting more fuel through nozzle 79.

Fuel leaving nozzle 79 is directed sideways out through apertures 109 generally crosswise to the stream of air through air horn 15. Such crosswise direction of fuel at an angle to the stream of air through the air horn atomizes the fuel more completely than a conventional downstream direction of fuel from a carburetor venturi. The well-atomized fuel is mixed both in the air horn and in the intake manifold below the throttle valve 46 for delivery of an even and uniform mixture to the engine.

For slow speed and relatively load-free driving, power diaphragm is positioned through follower pin 48 by throttle cam 47 and power disk 35. This results in leanest and most economical engine operation. For higher speeds and increased loads, such as hill climbing, headwinds, trailer-pulling, etc., the vacuum in chamber 37 is decreased because the engine runs a little slower and the throttle is open wider. This causes power spring 34 to raise disk 35 and power diaphragm 30 above follower pin 48. Under such conditions, regulator diaphragm 29 is held higher for enriching the fuel mixture injected into the engine by increasing the pressure of fuel delivered to the metering device. The enriched mixture helps the engine meet the load conditions, and the capacity for such enrichment enables a normally lean and economical operation. Thus, the interaction between intake manifold pressure (as transmitted to chamber 37) and power spring 34 compensates accurately for engine load and high speeds, to deliver the precise fuel-air mixture required by the engine under both light and heavy loads.

For sudden and rapid accelerations, throttle 46 is opened rapidly to drive follower pin 48 suddenly upward. This rapidly elevates both power diaphragm 30 and regulator diaphragm 29 to evacuate fuel from chamber 44 into regulator delivery passage 42 and on to metering means 12. This surge of extra fuel from chamber 44 increases the pressure of fuel delivered to the metering means and enriches the fuel-air mixture for rapid acceleration. This feature allows the full performance of the engine to be realized quickly.

The same mechanism operates in reverse to suddenly restrict the fuel supply for rapid deceleration. If the throttle is suddenly closed, follower pin 48 is dropped to the position illustrated in FIG. 5, and throttle valve 46 is nearly closed. This produces a very high vacuum in chamber 37 and draws power diaphragm 30 and power disk 35 down suddenly to their lowest positions. The sudden fall of power diaphragm 30 allows regulator spring 26 and regulator valve pin 23 to push regulator diaphragm 29 downward suddenly. This not only rapidly reduces the pressure of fuel delivered from regulator 10, but enlarges chamber 44 to further reduce the fuel pressure by drawing fuel into chamber 44. At the same time, air valve 14 nearly closes because of greatly reduced air flowing through air horn 15, and this reduces to a minimum the aperture opening set by metering pin 76 to suddenly restrict fuel injected through nozzle 79 to the trickle of fuel delivered for idling speed. These adjustments keep deceleration fuel to a minimum and produce maximum braking force from the engine.

Conventional carburators cannot so restrict the fuel during decelerations since abnormally high intake manifold vacuum draws considerable fuel through the idling jets. Such fuel is unwanted during deceleration, and cannot be burned from lack of air in the engine, resulting in great waste and emission of polluting fumes into the atmosphere. Such fumes are known to all motorists as the bluish wisps of smoke from the exhaust of the car ahead when it decelerates. Reducing this waste saves much fuel and greatly reduces the air pollution from an internal combustion engine. The reduction of pollutants by the inventive system is considerable in stop-and-go driving in city traffic where pollution is a more serious problem.

Throughout the operation of the inventive system, any vapor created in the fuel, as by heat from the fuel pump or the engine, is removed in vapor separator 11 and fed back to the tank. The adjustment of stop screw 66 prevents complete closure of valve pin 60 in vapor separator 11 and maintains a minimum bleed of vapor and fuel from separator 11 to the tank during engine operation. If more fuel is vaporized, float chamber 52 collects a relatively higher proportion of vapor to fuel, and float 57 sinks deeper into chamber 52 because of less fuel to support it in floatation. This lowers valve pin 60 and enlarges the openings to vapor escape passage 65 so that the increased vapor can return to the tank more rapidly. This allows rapid devaporization of the system and yet insures accurate pressure regulation and avoids the pressure reduction difliculties of an overabundant fixed bleed. The symmetrical arrangement of ports 62 opening to passage 65 helps prevent any binding or sticking of valve pin 60 and insures smooth and accurate operation of such valve.

The inventive vapor separator eliminates all emission of vapor into the atmosphere from the fuel system (except for the normal storage tank vent). Vapor escaping from conventional carburators contributes substantially to air pollution, and such emission is eliminated. by the inventive system. Return of vapor from metering device 12 to vapor separator 11 allows devaporization of fuel immediately before its metering to nozzle 79 and insures optimum, vapor-free injection.

Vapor separation in the inventive system is enhanced by the insulation of important parts of the system from engine heat. Insulator member 39 protects the fuel portion of the pressure regulator and the vapor separator from engine heat, and metering device 12 is preferably insulated from relatively hot body 9 by a heat insulating member to protect fuel in its reservoir from vaporization. The bleed from the vapor separator is operable after the engine is shut down, and under conditions in which conventional carburators cook the fuel and emit vapors from the vents for their floatation chambers, the inventive system bleeds vapor and fuel under pressure back to the tank without waste or air pollution.

If the engine is stopped either intentionally or accidentally, air valve 14 closes regardless of throttle position and O-ring 87 on metering pin 76 seats against aperture bushing 88 to shut off fuel to nozzle 79 completely. The fuel pressure of the system is gradually reduced by the bleed through vapor passage 65 to the storage tank, and since the system lacks open or ventilated reservoirs, the fuel system is effectively sealed off from leakage as soon as the engine stops. This greatly reduces the fire hazard from automobile accidents, since fuel cannot leak out onto a hot engine or exhaust manifold and start a fire adding to the disaster. This alone could reduce traffic fatalities.

The essential difference in operation of the inventive injection system with the single-diaphragm pressure regulator 10 is that fuel pressure controlled by regulator 10' is not responsive to intake manifold vacuum. Pressure regulation with regulator 10' is a function of throttle position and fuel delivery pressure as exerted against the upper surface of diaphragm 125 in chamber 44. The other elements of the inventive system function as previously described.

As illustrated in FIG. 6, in the dead-engine position, diaphragm 125 is in its lowermost position, since follower pin 48 is at the bottom of its travel. In such condition, the regulator valve is nearly closed to the position for normal idle; the lack of fuel pressure in chamber 44 allows expansion of regulator spring 119 and elevation of diaphragm 125 slightly above the normal idle position. As the engine is cranked, fuel pressure is built up in chamber 44, compressing regulator spring 119 and lowering diaphragm 125 to the idle position. This results in an initial supply of fuel at slightly above idling pressure, and quick reduction of fuel pressure to idle pressure as the engine is cranked. If the engine is cold, the starting enrichment mechanism advances throttle cam 47 to a fast idle position as described above, and this raises coupler 120, compresses regulator spring 119 to some extent, and raises diaphragm 125 to increase fuel pressure for an enriched starting mixture.

After engine warm-up, fuel pressure from regulator returns to a normal minimum for idle, and thereafter, delivery fuel pressure is regulated by the position of throttle cam 47. Regulator spring 119 positions diaphragm 125 vertically relative to coupler 120 as a function of fuel pressure in chamber 44, thus compensating for fuel pressure variations such as reduced pressure in incoming fuel or delivery fuel pressure reduction under high fuel flow. Pressure regulator 10' thus operates independently of intake manifold vacuum.

Power enrichment in response to reduced manifold vacuum is not achieved by regulator 10, but the overall fuel injection results are nevertheless excellent. Proper shaping of throttle cam 47 can produce the desired economy or performance at any throttle opening. Also, independence from manifold vacuum insures against an unwanted enrichment of the fuel-air mixture from a drop in such vacuum caused by malfunction of the engine such as from improper timing, worn valves, worn piston rings, etc. Furthermore, regulator 10 requires fewer parts and adjustments, and is simple to manufacture and maintain.

Like pressure regulator 10, reguluator 10 also provides rapid acceleration enrichment as diaphragm 125 is driven rapidly upward in response to a sudden opening of the throttle to evacuate fuel from chamber 44 and increases the pressure in delivery passage 42, During deceleration, diaphragm 125 is dropped to its lower-most position as the throttle is closed and fuel injection is limited to idling pressure as described above.

Thus, it can be seen that the invention accomplishes its objects. The inventive system injects into the engine fuel-air mixtures that are well atomized and mixed and optimum for all conditions of operation. Furthermore, the preferred illustrated embodiment is interchangeable with a conventional carburetor, is a simple and economically made device, and is reliable and easily maintained.

The inventive injector is compatible with all conventional automotive equipment and through vacuum connector socket 110 the usual vacuum accessories can be connected to it. The inventive system promotes safety in increasing the braking force of a decelerating engine and in shutting off and scaling up the fuel system when the engine stops. The system also greatly reduces air pollution from internal combustion engines and is both economical of fuel and able to realize the engines perform ance potential.

Other features, advantages, and other specific embodiments of this invention will be apparent to those exercising ordinary skill in the pertinent art after considering the foregoing disclosure. In this regard, while specific preferred embodiments of my invention have been described in considerable detail, such disclosure is intended as illustrative, rather than limiting, and other embodiments, variations, and modifications can be effected within the spirit and scope of the invention as disclosed and claimed.

I claim:

1. A fuel injection system for an internal combustion engine having an intake passage, a throttle valve, and a source of fuel under pressure, said system comprising:

(A) means for metering said fuel into said intake passage, said metering means comprising:

(1) means for sensing the movement of air in said intake passage;

(2) a movable fuel-metering valve for controlling an opening through which said fuel is admitted under pressure to said intake passage; and

(3) means for interconnecting said fuel-metering valve and said sensing means to position said fuel-metering valve as a function of said air movement;

(B) means for variably regulating the pressure of fuel at said metering means, said regulating means comprising:

( 1) an inlet for receiving fuel from said source;

(2) an outlet for delivering fuel at a variable pressure lower than the pressure of fuel from said source;

(3) a movable fuel-pressure-regulating valve disposed between said inlet and said outlet;

(4) a spring arranged for biasing said fuel-pressure-regulating valve toward a seated position;

(5) a movable diaphragm engaging said fuelpressure-regulating valve and communicating with fuel in said outlet;

(6) a spring arranged for biasing said diaphragm against said valve in opposition to said valve bias spring and to fuel pressure in said outlet;

(7) a movable member engaging said diaphragm bias spring; and

(8) means movable with said throttle for positioning said movable member to vary said bias on said diaphragm for variably regulating said pressure; and

vapor separator means comprising:

(1) A fuel passageway arranged between said pressure regulator and said metering means; (2) a chamber arranged generally below said passageway and in communication with said passageway for containing a quantity of said fuel under pressure.

(3) float means disposed in said chamber in equilibrium relative to the pressure within said chamber, said float means being movable as a function of the fuel-to-vapor ratio in said chamber;

(4) a vapor valve slidable axially within said passageway;

(5) said chamber being configured to communicate with both axial ends of said vapor valve to subject both axial ends of said vapor valve to said pressure of said fuel in said chamber so that vapor valve is axially in equilibrium relative to said fuel pressure;

(6) said passageway being configured to define a vapor outlet passage disposed radially of said vapor valve'and leading to a lower pressure region; and

(7) means for positioning said vapor valve in response to the position of said float means as a function of the fuel-to-vapor ratio in said chamber.

2. The system of claim 1 wherein said intake passage comprises an intake manifold and an inlet body secured to said intake manifold, a meter body housing said metering means is disposed outside of and secured to a side wall of said inlet body, a regulator body housing said 13 pressure regulator and said vapor separator is disposed outside of and secured to a side wall of said inlet body, and heat insulation means are disposed between said inlet body and said meter body housing and between said inlet body and said regulator body housing.

3. The system of claim 1 including means for positioning said diaphragm as a function of the pressure in said intake passage on the engine side of said valve.

4. The system of claim 1 including means for positioning said diaphragm as a function of atmospheric pressure.

5. The system of claim 1 wherein said source of fuel comprises a storage tank and a fuel pump, said pressure regulator is arranged for receiving fuel from said pump, said storage tank comprises said lower pressure region, and said vapor outlet passage means leads to said tank.

6. The system of claim 5 including a stop means for engaging said vapor valve for preventing complete closure of said vapor oulet passage to provide a continuous bleed through said vapor oulet passage to said tank.

7. In a fuel injection system for an internal combustion engine having an intake passage and a source of fuel under pressure, means for metering said fuel into said intake passage, said metering means comprising:

(a) means for receiving said fuel under pressure;

(b) an air valve for sensing the movement of air in said intake passage;

(c) nozzle means for delivering fuel under pressure into said intake passage;

((1) a movable fuel-metering valve in communication with said nozzle means for controlling an opening through which said fuel is admitted to said nozzle means;

(e) means for interconnecting said fuel-metering valve and said sensing means to position said fuel-metering valve as a function of said air movement;

(f) said metering valve comprising a shaped pin disposed within said opening and movable axially for controlling the size of said opening;

(g) means for shutting off fuel to said openings,

'(h) a pin-supporting member and a dashpot for containing a quantiy of said fuel arranged so that one end of said pin is formed as a piston slidable in said dashpot and the other end of said pin is seated in said pin-supporting member with said pin being centered axially in said opening and held from engagement with said opening;

(i) a compression spring engaging said piston andbiasing said pin toward a closed-valve position, and a member coupled to said pin-supporting member and said air valve for urging said pin toward openvalve positions in response to opening of said air valve; and

(j) an intake passage comprising an air horn and in intake manifold, said air valve comprising a plate eccentrically pivotal within said air horn so as to turn toward an upright position in response to movement of air in said air horn, and said coupling means comprising an equalizer bracket connected to the upturning side of said air valve and engaging said pinsupporting member.

8. The metering means of claim 17 including a body housing said metering valve and said dashpot, said body being outside, and secured to, said air horn and disposed so that said dashpot and said pin slope upwardly toward said nozzle.

9. The metering means of claim 8 wherein heat insulation means is disposed between said body and said air horn.

10. The metering means of claim 8 wherein said body in an upper region of said dashpot is formed to define a vapor passage leading from said dashpot to a region of lower pressure.

11. In a fuel injection system for an internal combustion engine having an intake passage, a throttle valve, and a source of fuel under pressure, means for variably regulating the pressure of fuel delivered to said intake passage, said regulating means comprising:

(a) an inlet for receiving fuel from said source; (b) an outlet for delivering fuel at a variable pressure 5 lower than the pressure of fuel from said source;

(0) a movable fuel-pressure-regulating valve disposed between said inlet and said outlet;

(d) a spring arranged for biasing said fuel-pressureregulating valve toward a seated position;

(e) a movable regulator diaphragm engaging said fuel-pressure-regulating valve and communicating with fuel in said outlet;

(f) a spring arranged for biasing said regulatordiaphragm against said valve in opposition to said valve bias spring and to fuel pressure in said outlet;

(g) a movable member engaging in said regulator diaphragm bias spring; and

(h) means movable with said throttle for positioning said movable member to vary said bias on said regulator diaphragm for variably regulating said pressure.

12. The pressureregulating means of claim 11 wherein said means movable with said throttle valve comprises a cam and a follower therefor.

13. The pressure-regulating means of claim 11 wherein one surface of said regulator diaphragm communicates with the atmosphere.

14. The pressure-regulating means of claim 11 in cluding a bafile arranged in the region of the higher pressure side of said valve.

15. The pressure-regulating means of claim 11 including intake means for said engine, means for sensing air movement in said intake means, and means responsive to said sensing means for metering fuel from said outlet into said intake means.

16. The pressure-regulating means of claim 11 including means for adjusting said va1ve-biasing spring to regulate minimum fuel pressure for idling.

17. The pressure-regulating means of claim 16 wherein said adjusting means comprises a threaded member engaging in said valve-biasing spring and communicating with said fuel and having an annular groove, and an O-ring disposed in said groove for sealing said member in any adjusted position.

18. The pressure'regulating means of claim 11 including means for positioning said regulator diaphragm as a function of the pressure in said intake passage on the engine side of said throttle valve.

19. The pressure-regulait-ng means of claim 18 including a power diaphragm engaging said movable member and communicating with said intake passage on the engine side of said throttle valve.

20. The pressure-regulating means of claim 19 including means arranged for venting the space between said regulator diaphragm and said power diaphragm to atmosphere.

2,1. The pressure-regulating means of claim 19 including a spring biasing said power diaphragm in opposition to vacuum in said intake passage on the engine side of said throttle valve.

22. The pressure-regulating means of claim 21 wherein said member movable with said throttle valve comprises a cam and a follower therefor.

23'. The pressure-regulating means of claim 22 wherein said outlet is formed to define a chamber normally filled with fuel communicating with said regulator diaphragm so that movement of said power diaphragm in response to rapid opening of said throttle urges said regulator diaphragm into said chamber to force said fuel therein from said regulating means through said outlet for enriching the fuel-to-air ratio in said intake passage for rapid acceleration.

24. In a fuel injection system for an internal combustion engine having an intake passage and a source of fuel under pressure, vapor separating means comprising:

(a) a fuel passageway arranged between said source and said intake passage;

(b) a chamber arranged generally below said passageway and in communication with said passageway for containing a quantity of said fuel under pressure;

(c) float means disposed in said chamber in equilibrium relative to the pressure within said chamber, and float means being movable as a function of the fuel-to-vapor ratio in said chamber;

(d) a vapor valve slidable axially within said passage-- (e) said chamber being configured to communicate 'with both axial ends of said vapor valve to subject both axial ends of said vapor valve to said pressure of said fuel in said chamber so that said vapor valve is axially in equilibrium relative to said fuel pressure;

(f) said passageway being configured to define a vapor outlet passage disposed radially of said vapor valve and leading to a lower pressure region; and

(g) means for positioning said vapor valve in response to the position of said float means as a function of the fuel-to-vapor ratio in said chamber.

25. The vapor separating means of claim 24 wherein said vapor outlet passage is arranged in radial symmetry around said vapor valve.

26. The vapor separating means of claim 24 wherein said source of fuel comprises a storage tank and a fuel pump, and said vapor outlet passage leads to said tank.

27. The vapor separating means of claim 26 including a stop means engaging said vapor valve for preventing complete closure of said vapor outlet passage to provide a continuous bleed through said vapor outlet passage to said tank.

28. The vapor separating means of claim 27 including a baflie arranged within said chamber to reduce the effect upon said float means of turbulence in said fuel, means for guiding said float means for vertical movement, and means for spacing a large portion of the bottom of said float means from the bottom of said chamber when said float means is in its lowermost position.

29. In a fuel injection system for an internal combustion engine having an intake manifold and a source of fuel under pressure, means for variably regulating the pressure of fuel delivered to said engine, said regulating means comprising:

(a) an inlet for receiving fuel under pressure from said source;

(b) an outlet for delivering fuel at a variable pressure lower than the pressure of fuel from said source;

(c) a movable fuel-pressure-regulating valve disposed between said inlet and said outlet;

((1) a power diaphragm in communication with said intake manifold and positioned as a function of pressure in said intake manifold;

(e) a regulator diaphragm in communication with fuel in said outlet and positioned in response to the position of said first diaphragm;

(f) a spring arranged for biasing said fuel-pressureregulating valve toward a seated position;

(g) said regulator diaphragm engaging said fuelpressure-regulating valve in opposition to said valve bias spring;

(h) a compression spring disposed between said power diaphragm and said regulator diaphragm; and

(i) a spring arranged for biasing said power diaphragm in opposition to intake manifold vacuum.

30. The pressure-regulating means of claim 29 including means for venting to atmosphere the space between said power diaphragm and said regulator diaphragm.

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3,198,497 8/1965 Mennesson 26150.1 X 3,207,491 9/ 1965 Kingsley et a1. 261-44 3,249,346 5/1966 Bickhaus et a1 261-50.1 3,294,377 12/1966 Smith 261-50.1 X 3,301,536 1/1967 Swatman 26l-50.1 X 3,322,408 5/1967 Stoltman 261-50.1 X 3,350,073 10/1967 Hill 261-50.1 X 3,362,694 1/1968 Gould 261-50.1 X

TIM R. MILES, Primary Examiner.

US. Cl. X.R. 

